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Blaster Cylinder / piston diagnosis

7K views 8 replies 5 participants last post by  POUNDSAND 
#1 · (Edited)
Ok.. I am a 4-stroke guy in need of a little 2-stroke advice.. My kid's Blaster and I just got done rehoning the cylinder and dropping in a new wiseco piston. The honing device was one of the size match / attach to your drill jobs. The cylinder wasnt perfect but was pretty good. Bike ran fine for about an hour and then BAM! Right back to not starting. Take a look at the pics below and let me know the reason for the problem.

My question is this:

A: Is this bike being starved of oil. It curently has the auto oil injection and I am not opposed to disconnecting and premixing if it means this doesnt happen again.

B: was the cylinder simply not clean enough and it chewed up the piston again?

C: Is there something foreign down inteh crank causing the piston to chew up?

Any help I could get is greatly apprecieated. I plan to take the cylinder in and get in bored out and cleaned up at a local machine shop. Any idea what that should cost me?

Thanks Fellas...

Spark Plug looked like this:


Cylinder looked like this:





Piston looks like this:





oh yeah.. I just got my mount back from my taxidermist today. It's enroute to my house as of today. My buck I got last year in Colorado.. My wife is feaking out. It's going over my safe in the family room.. :banana: Aint she purdy...

 
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#2 ·
looks like it wasnt getting oil. i would premix it and not use the stock oil injector. i think there is a block off plate or something for the oil injector you can buy. i would say it wasnt getting oil and started getting hot and galled the rings to the piston. i let a friend borrow my 250r one time and he put race gas in it instead of the fuel i gave him, ended up with the same thing you have and a cracked sleeve.

found the block off kit OIL BLOCK OFF KIT ::...
 
#5 ·
I did not do any measuring before installation and thats probably where I went wrong.... I orderred a stock bore (66mm) piston and dropped it in thinking it would be correct. There is a "no oil" light on the dash that turns off after a few seconds..

I will for sure disconnect the automatic injection and pre-mix from here out.. If I get the cylinder cleaned up and bored out and have a piston to match it, Is my problem solved?

Thanks so much fellas/ your opinions are greatly respected and apprecieated..
 
#7 ·
the machine shop i use they wont bore a block without the piston that is going in it. thats how we did it when i went to tech school to. we numbered the pistons to what bore they went into. one cummins i had done there was a .0045 difference between the six pistons and they were high$ aftermarket pieces. have the machine shop clean it up and see where you are at, then you can get the next size up. im sure you can give them the rings and have them fitted to. my "friend" put a couple hours on mine before he couldnt get it to start anymore.
 
#9 ·
Just to update y'all on this thread.. I sent the cylinder out to John at Racer's Edge to hone and match up with a piston. Great guy by the way and he earned my future business...

I installed the new setup and it ran great for a few minutes. It started not running right again and I shut it down. I then realized by replacing the piston, I was only fixing a sympton and really not the problem. I then removed the oil pump, drained out the premix and blocked it from flowing to the carb. I then manually premixed my fuel at 32:1 and restarted. She is running like a champ now and is snappier then ever.

I also orderred a new case gasket and when it comes in I will remove the impellor off the oil pump to prevent the pump from turning. I thnk I have it licked...

Thanks to Racers Edge and HDD as well as everyone elsewho lended their input. :thumb:

Glamis in two weeks for Turkey Lurkey week and my kid will get to run his ride. He's like this :hyper:.....
 
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